Synthesis and evaluation of hydroxypropylated potato starch as polymeric support for benzo[a]pyrene degradation by Fenton reaction

In order to perform an efficient Fenton reaction of benzo[a]pyrene (BaP) in the presence of starch as a reaction matrix, a computer modeling study conducted on amylopectin as a component of potato starch allows to identify three more stable sites, among six, available for BaP and iron complexation. For the purpose of enabling the formation of such a stable complex, starch was irreversibly modified by hydroxypropylation for favoring the accessibility of BaP to available complexation sites. The results show that such an irreversible modification significantly consequently increased starch solubilization in cold water. Hydroxypropyl starch derivative obtained in the optimized synthesis conditions (molar substitution of 0.73) increased significantly the BaP solubility and consequently influenced its degradation (38%) by Fenton oxidation. We might hypothesize that starch depolymerisation occurring through a radical chain mechanism during the Fenton reaction allows the formation of carbon centred radicals, permitting therefore an oxidation attack of BaP.